Resilient charging station

ABSTRACT

In order to ensure continued charging of electric vehicles when a charging station is not currently received an input power from an external power source, the systems and methods disclosed herein provide for operation of the charging station in a resilient operating mode in which an operating current is derived from a charge previously stored in a battery of the charging station. The operating current is produced by a resilient power subsystem within the charging station using the stored charge and is provided by the resilient power subsystem to one or more system components within the charging station in order to enable continued operation of the charging station, including enabling continuing vehicle charging during a time interval in which the charging station is not receiving input power from an external power source.

TECHNICAL FIELD

At least one aspect generally relates to improvements to vehiclecharging stations generally and more particularly to improvementsenabling vehicle charging stations to continue operation whendisconnected from an electric power grid or other external power source.

BACKGROUND

Charging stations provide electric power to electric vehicles (EVs),including plug-in hybrid vehicles, that can operate without the use orwith limited use of hydrocarbon-based fuels. Installation ofconventional charging stations typically requires improvements toinfrastructure including upgrades to electrical service and constructionof suitable housing. The costs, planning, and time required to installthese charging systems can be a deterrent to potential commercial orresidential operators. To reduce the installation and operatingrequirements associated with traditional charging stations, somecharging stations include batteries to store energy received from apower source (such as an electric utility power grid) over an extendedtime interval. While such charging stations are thus enabled to chargeEVs at a faster rate, an external power source is still needed toprovide power to the controllers, display screens, sensors, temperaturecontrol systems, and various other components of the charging stations.Thus, despite including batteries that store power to charge EVs, suchcharging stations nonetheless become inoperative if their external powersource fails or becomes disconnected. Therefore, improved systems andtechniques for ensuring resilient operation of charging stations areneeded in order to continue vehicle charging despite temporaryunavailability of external power sources.

SUMMARY

The systems, methods, and computer-readable instructions disclosedherein solve the problem of ensuring resilient operation of a chargingstation through the use of a resilient power subsystem configured toprovide power to system components of the charging station duringtemporary disconnection or other unavailability of an external powersource. As described herein, a vehicle charging system for charging avehicle is provided, the vehicle charging system comprising: (i) a powerinput port configured to receive input electric power from a powersource at a first voltage (V₁); (ii) a plurality of batteries configuredto receive a direct current (DC) input current derived from the inputelectric power received at the power input port and store electric powerfrom the DC input current; (iii) a vehicle coupling configured toreceive a DC charging current at a second voltage (V₂) derived from theplurality of batteries and to provide an electrical interconnect betweenthe vehicle charging system and the vehicle in order to provide the DCcharging current to the vehicle; (iv) a resilient power subsystemconfigured to provide a DC operating current at a third voltage (V₃)derived from the electric power stored in at least one of the pluralityof batteries to a plurality of system components within the vehiclecharging system that are configured to control operation of the vehiclecharging system; and (v) a system controller comprising one or moreprocessors configured to control operation of the vehicle chargingsystem, which system controller may be one of the plurality of systemcomponents. In some embodiments, the system controller controlsresilient operation of the vehicle charging system by receiving the DCoperating current during a time interval in which the input electricpower is not being received from the power source and controlling thevehicle charging system to provide the DC charging current to theelectrical interconnect to charge the vehicle during the time interval.The plurality of system components may comprise a plurality oftemperature control components configured to maintain an internaltemperature of the vehicle charging system within an operating range,such as coolant pumps, fans, or heating elements.

The vehicle charging system may receive the input electric power as analternating current (AC) input electric power from an electric powergrid. Thus, the vehicle charging system may further comprise a rectifierconfigured to receive the AC input electric power and provide the DCinput current to the plurality of batteries. The DC input current may beselected to be any desirable voltage. In some embodiments, each of theplurality of batteries stores the electric power at a fourth voltage(V₄), with the second, third, and fourth voltages satisfy the followingcriteria: V₃<V₄<V₂. In some such embodiments, the resilient powersubsystem comprises a step-down converter configured to receive abattery current from the at least one of the plurality of batteries atthe fourth voltage (V₄) and provide the DC operating current at thethird voltage (V₃) to the plurality of system components. In furtherembodiments, the resilient power subsystem comprises an DC busconfigured to provide the DC operating current to the plurality ofsystem components. In various embodiments, the resilient power subsystemmay comprise one or more of the following: power conversion circuits(including rectifiers, inverters, buck-boost converters, step-upconverters, or step-down converters), controllers (including modulesrunning on the system controller or separate control circuits),batteries (including the plurality of batteries used to charge vehiclesor separate backup batteries), or various busses and other connectionsbetween components.

The system components also receive the DC operating current needed foroperation of the vehicle charging system during a second time intervalin which the input electric power is being received from the powersource. In various embodiments, the system components may receive the DCoperating current during the second time interval from either theresilient power subsystem or from a primary power subsystem. Inembodiments in which the DC operating current is received from theresilient power subsystem during the second time interval, the systemcontroller may be configured to receive the DC operating current fromthe resilient power subsystem during the second time interval andcontrol the vehicle charging system to provide the DC charging currentto the electrical interconnect to charge the vehicle during the secondtime interval. In embodiments in which the DC operating current isreceived from the primary power subsystem during the second timeinterval, the system controller may be configured to receive the DCoperating current from the primary power subsystem during the secondtime interval, detect a triggering condition indicating the inputelectric power is not being received from the power source at thebeginning of the time interval. and cause the resilient power subsystemto begin providing the DC operating current during the time interval inresponse to detecting the triggering condition.

Methods or computer-readable media storing instructions for implementingall or part of the vehicle charging system described above may also beprovided in some aspects in order to provide or operate a vehiclecharging station. According to some aspects, an exemplary method forcharging a vehicle by a vehicle charging system comprises: receiving aninput electric power from a power source at a first voltage (V₁) at apower input port of the vehicle charging system during a first timeinterval; charging a plurality of batteries of the vehicle chargingsystem using a DC input current derived from the input electric powerreceived at the power input port by storing a charge in the plurality ofbatteries during the first time interval in which the input electricpower is being received from the power source; determining occurrence ofa triggering condition by a system controller of the vehicle chargingsystem, the triggering condition indicating the input electric power isnot being received from the power source; and in response to determiningoccurrence of the triggering condition, controlling the vehicle chargingsystem by the system controller during a second time interval in whichthe input electric power is not being received from the power source to:(i) provide a DC charging current at a second voltage (V₂) derived fromthe plurality of batteries to the vehicle via a vehicle coupling inorder to charge a vehicle battery of the vehicle and (ii) provide a DCoperating current at a third voltage (V₃) by a resilient powersubsystem, the DC operating current being derived from the electricpower stored in at least one of the plurality of batteries to aplurality of system components within the vehicle charging system,wherein the system components are configured to control operation of thevehicle charging system. Additional or alternative features describedherein may be included in some aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of an example of a charging sitehaving multiple vehicle charging systems powered by an electric powergrid in accordance with certain aspects disclosed herein.

FIGS. 2A-C illustrate block diagrams of various examples of an electricvehicle charging system configured for resilient vehicle charging inaccordance with certain aspects disclosed herein.

FIG. 3 illustrates a flow diagram of an example resilient chargingmethod for operating a resilient charging system to continue vehiclecharging despite disconnection from or failure of a power source inaccordance with certain aspects disclosed herein.

FIG. 4 illustrates a block diagram illustrating a simplified example ofa hardware implementation of a controller in accordance with certainaspects disclosed herein.

DETAILED DESCRIPTION

The techniques disclosed herein generally relate to solving the problemof ensuring continued operation of an electric vehicle charging stationwhen the charging station is temporarily disconnected from an externalpower source or when the power source is otherwise unavailable. In orderto ensure resilient operation during time intervals in which an inputelectric power is not received from an external power source, thevehicle charging station includes a resilient power subsystem configuredto convert a charge stored in one or more batteries of the chargingstation into one or more operating currents, which operating currentsare supplied by the resilient power subsystem to various systemcomponents within the charging station in order to enable continuedoperation of the charging station. Such operating currents may bealternating current (AC) or direct current (DC) operating currents invarious embodiments. Since the charging station is configured to chargevehicles using the charge stored in its batteries, the charge station isthus enabled to continue operating to charge vehicles even when it isnot drawing power from the external power source. Additional oralternative features are described in further detail below.

Several aspects of electric vehicle (EV) or plug-in hybrid vehiclecharging systems will now be presented with reference to variousembodiments. Although described herein as relating to EVs, it should beunderstood that the techniques may be applied equally to plug-in hybridvehicles or other wholly or partially battery-powered devices that maybe charged by a high-voltage or high-power charging station. Chargingstations are used for recharging batteries in EVs by supplying AC or DCpower to EVs. In turn, the charging stations receive an input electricpower supplied by an external power source, such as a utility power gridconnection or local power source (e.g., solar, wind, water, orhydrocarbon-powered power generation systems). The charging stationsdescribed herein store power in one or more internal or connectedbatteries in order to smooth power consumption over time. In addition tousing such stored power to charge EVs, the charging stations are furtherconfigured to use such stored power to provide one or more operatingcurrents to system components within the charging stations whenoperating in a resilient operating mode during a time interval in whichan input electric power is not being receive from an external powersource.

FIG. 1 illustrates a block diagram of an example of a charging site 10with multiple EV charging systems 100A-D1. The charging site 10 issupplied with AC power from an electric power grid 20 via a local ACcircuit 21 and a site meter 22, which records power consumption andconnects the various electrical components disposed at the charging site10 to the electric power grid 20. Thus, the electric power grid 20provides AC power to each of the EV charging systems 100A-D and otherelectrical components via the site meter 22, including providing ACpower to a non-charging load 24 (e.g., commercial building electricalinfrastructure) at the charging site 10. In some embodiments, the sitemeter 22 is a smart meter including additional control logic andcommunication functionality. For example, the site meter 22 may beconfigured to communicate with one or more external servers (not show)and/or the centralized management system 150 to obtain demand dataregarding load on or demand charges for AC power from the electric powergrid 20. In some such embodiments, the site meter 22 may be configuredto disconnect part or all of the loads from the electric power grid 20upon the occurrence of certain conditions (e.g., during peak hours orwhen the power grid is unstable due to high demand). In this way, thesite meter 22 may be used to separate the local AC circuit 21 of thecharging site 10 from the electric power grid 20 when needed. Althoughonly one site meter 22 is shown, some embodiments may include aplurality of meters, each of which may perform part or all of theoperation of the site meter 22. Such embodiments may be implemented tofacilitate more targeted control of operations of individual EV chargingsystems 100 or non-charging loads 24 at the charging site 10.

The AC power from the site meter 22 is provided as an AC input electricpower to the respective input ports 102A-D of the EV charging systems100A-D via one or more wired AC connections of the local AC circuit 21.In some embodiments, the AC input electric power is received at each ofthe input ports 102A-D as a 120V or 240V single-phase or three-phase ACpower supply. As discussed elsewhere herein, each of the EV chargingsystems 100A-D converts and stores such AC input electric power to DCpower stored in batteries of respective energy storage modules 114A-D,from which charging currents may be provided to vehicles via vehiclecouplings 132A-D of the EV charging systems 100A-D. The EV chargingsystems 100A-D are controlled by respective system controllers 120A-D,which monitor operating data of the respective EV charging systems100A-D and control charging and discharging of the energy storagemodules 114A-D.

In some embodiments, the DC power may be stored in the energy storagemodules 114A-D over an interval of time in order to provide chargingcurrent to EVs via respective vehicle couplings 132A-D at a faster ratethan the AC input electric power is received by the EV charging systems100A-D. While this has significant advantages in reducing the electricalinfrastructure requirements for the charging site 10, some of the EVcharging systems 100A-D may be used more than others. For example, EVcharging systems 100C and 100D may experience greater use due to closerproximity to a destination (e.g., by being located in a parking lot atlocations nearer an entrance to a commercial building). As illustrated,vehicles 140C and 140D may be connected to EV charging systems 100C and100D by vehicle couplings 132C and 132D, respectively, in order toreceive charging currents from energy stored in the energy storagemodules 114C and 114D, while no vehicles are charging at EV chargingsystems 100A and 100B. Thus, the batteries of EV charging systems 100Cand 100D will discharge faster than those of EV charging systems 100Aand 100B, resulting in a charge imbalance among the energy storagemodules 114A-D. To address such an imbalance, in some embodiments,energy may be transferred from EV charging systems 100A and 100B to EVcharging systems 100C and 100D via the local AC circuit 21. In someembodiments, one or more external battery systems 30 are also connectedto the local AC circuit 21 to store energy and provide it to the EVcharging systems 100A-D at a later time, which external battery systems30 may include controllers (not shown) or may be controlled by acentralized management system 150. Similarly, in various embodiments,charge transfers may be determined and controlled by the systemcontrollers 120A-D of the EV charging systems 100A-D or by a centralizedmanagement system 150. To facilitate such control decisions, each of thesystem controllers 120A-D may be connected via wired or wirelesscommunication connections with the other system controllers 120A-Dand/or with the centralized management system 150 to exchange electronicmessages or signals.

The centralized management system 150 may communicate with each of theEV charging systems 100A-D in order to monitor operating data regardingthe EV charging systems 100A-D and to determine control actions to beimplemented by the EV charging systems 100A-D as needed. The centralizedmanagement system 150 may be located at the charging site 10 or at alocation remote from the charging site 10. When remote from the chargingsite 10, the centralized management system 150 may be communicativelyconnected to the EV charging systems 100A-D via a network 40, which maybe a proprietary network, a secure public internet, a virtual privatenetwork, or some other type of network, such as dedicated access lines,plain ordinary telephone lines, satellite links, cellular data networks,or combinations of these. In various embodiments, the EV chargingsystems 100A-D may be communicatively connected with the network 40directly or via a local router 42. In some embodiments in which thecentralized management system 150 is located at the charging site 10,the centralized management system 150 may be combined with orincorporated within any of the EV charging systems 100A-D. In stillfurther embodiments, the centralized management system 150 may beconfigured as a local cloud or server group distributed across thesystem controllers 120A-D of the EV charging systems 100A-D in order toprovide robust control in the event of a network disruption.

In some embodiments, the centralized management system 150 may alsocommunicate with remote EV charging systems that are deployed inlocations remote from the charging site 10, which locations may beseparated by large geographic distances. For example, the centralizedmanagement system 150 may communicate with EV charging systems 100located in different parking facilities, on different floors of the sameparking structure, or in different cities. Such centralized managementsystem 150 may comprise one or more servers configured to receiveoperating data from and to send data and/or control commands to each ofthe EV charging systems 100A-D. To facilitate communication, thecentralized management system 150 may be communicatively connected tothe system controllers 120A-D of the EV charging systems 100A-D via anelectronic communication link with a communication interface module (notshown) within each of the EV charging systems 100A-D.

The centralized management system 150 may group or relate EV chargingsystems according to their location, their intended function,availability, operating status, and capabilities. The centralizedmanagement system 150 may remotely configure and control the EV chargingsystems, including the EV charging systems 100A-D. The centralizedmanagement system 150 may remotely enforce regulations or requirementsgoverning the operation of the EV charging systems 100A-D. Thecentralized management system 150 may remotely interact with users ofthe EV charging systems 100A-D. The centralized management system 150may remotely manage billing, maintenance, and error detection for eachof the EV charging systems 100A-D. For example, error conditionsresulting in manual disconnection of a vehicle from any of the EVcharging systems 100A-D may be reported by such EV charging system tothe centralized management system 150 for analysis. The centralizedmanagement system 150 may also communicate with mobile communicationdevices of users of the EV charging systems 100A-D, such as mobilecommunication devices or other computing devices used by operators ofthe EV charging systems 100A-D to enable the operator to self-configurethe EV charging systems 100A-D, charge pricing, language localization,currency localization, and so on. Operation of the centralizedmanagement system 150 in relation to charge transfers between the EVcharging systems 100A-D is further described elsewhere herein.

FIG. 2A illustrates a block diagram of an example of an EV chargingsystem 100 configured in accordance with certain aspects disclosedherein. The EV charging system 100 may be any of the EV charging systems100A-D at the charging site 10 illustrated in FIG. 1 . The EV chargingsystem 100 is configured to receive electric power from a power source(e.g., electric power grid 20) at a first voltage (V₁) via an input port102 or 104 in order to charge an energy storage module 114 (e.g., one ormore batteries), from which the EV charging system 100 provides acharging current at a second voltage (V₂) to a vehicle 140 in order tocharge a battery 148 of the vehicle 140. Such charge is provided througha vehicle coupling 132, which may comprise a charging cable utilizingone or more standard connector types (e.g., Combined Charging System(CCS) or Charge de Move (CHaDEMO) connectors). Various system componentsare disposed within the EV charging system 100 to perform aspects ofoperation of the EV charging system 100, each of which system componentsis configured to operating using an AC or DC operating current at athird voltage (V₃) that may differ between system components. A systemcontroller 120 receives a DC controller operating current at a thirdvoltage (V₃) and implements control logic to monitor operating data andcontrol operation of the EV charging system 100. Although theillustrated EV charging system 100 is illustrated as communicating witha centralized management system 150, alternative embodiments of the EVcharging system 100 need not be configured for such externalcommunication. Additional or alternative components and functionalitymay be included in further alternative embodiments of charging systems.

The EV charging system 100 includes a rectifier 110 having one or morecircuits configurable to transform, condition, or otherwise modify ACinput power received from an input port 102 or 104 to provide DC powerto a power conversion module 112. The input power received at inputports 102 or 104 may be received from an electric power grid 20, a localpower generator (e.g., a solar panel or a wind turbine), or any otherpower source. In some embodiments, AC input electric power is receivedat an AC input port 102, while input DC power is received at a DC inputport 104 (e.g., from photovoltaic cells or other types of DC powersources). The DC input port 104 may be connected to one or more of aninverter module 106 or a power conditioning module 108 for the input DCpower. In further embodiments, DC current received via DC input port 104is converted to an AC current by an inverter module 106, and the ACcurrent is then provided to the rectifier 110. The rectifier 110 mayconvert and combine AC currents received from multiple sources. In someembodiments, multiple rectifiers 110 may direct DC current derived frommultiple sources to individual circuits or sections of the powerconversion module 112. In further embodiments, DC current received viaDC input port 104 may instead be provided to a power conditioning module108 that may include voltage level converting circuits, filters, andother conditioning circuits to provide a charging current to the energystorage module 114.

The power conversion module 112 includes some combination of one or moreDC-to-DC converters for efficient conversion of DC input currentreceived from the rectifier 110 to a DC energy storage current 126provided to the energy storage module 114, which stores the power untilneeded to provide a charging current 116 to a vehicle 140. In someembodiments, the power conversion module 112 includes an DC-to-DCconversion circuit that generates a DC energy storage current 126 thatis provided to an energy storage module 114 at a voltage different fromthat of the AC input power received from at input port 102 from thepower source. Additionally or alternatively, the rectifier 110 mayinclude one or more AC-to-DC conversion circuits to generate a DCcurrent at any desirable voltage from an AC input electric power. Insome embodiments, the power conversion module 112 comprises one or moreDC-to-DC converters (e.g., step-up converters, step-down converters, orbuck-boost converters) to provide the energy storage current 126 at avoltage that is different from the first voltage (V₁) at which the inputpower is received at input port 102 or 104 or the voltage of the DCinput current received from the rectifier 110.

The energy storage module 114 comprises one or more batteries configuredto store a charge received from the power conversion module 112 or thepower conditioning module 108. In some embodiments, the one or morebatteries may be configured to store the charge at a fourth voltage (V₄)that is different from the first voltage (V₁) at which the input poweris received at input port 102 or 104. Such fourth voltage (V₄) may begreater than the third voltage (V₃) at which the system componentsoperate and less than the second voltage (V₂) at which the chargingcurrent is provided to a vehicle 140. The energy storage module 114 mayfurther comprise a battery management system to monitor and manage thecharge stored by the one or more batteries. In some embodiments, theenergy storage module 114 may comprise a plurality of high-capacitybatteries storing energy for charging vehicles and a backup battery 115storing energy for powering various system components of the EV chargingsystem 100 during a resilient operating mode without receiving inputpower from an external power source. Such backup battery 115 may store acharge at a voltage different from that of the voltage at which theother batteries of the energy storage module 114 store their charge. Forexample, in order to improve efficiency, the backup battery 115 maystore its charge at an operating voltage of the system components to bepowered by such backup battery 115.

In further embodiments, the energy storage module 114 includeshigh-capacity batteries that have a storage capacity greater than amultiple of the storage capacity in the EVs to be charged (e.g., threetimes, five times, or ten times an expected vehicle battery capacity).The storage capacity of the energy storage module 114 may be configuredbased on the expected average charge per charging event, which maydepend upon factors such as the types of vehicles charged, the depletionlevel of the vehicle batteries when charging starts, and the duration ofeach charging event. For example, a retail parking site may have morecharging events of shorter duration, while a commuter train parking lotmay have fewer charging events of longer duration. In variousembodiments, the storage capacity of the energy storage module 114 maybe configured based on maximum expected charging offset by powerreceived from an electric utility. In some embodiments, the storagecapacity of each of the energy storage modules 114 of the EV chargingsystems 100 and any external battery systems 30 at a charging site 10may be configured to ensure a total charge stored at the charging site10 is sufficient for an expected maximum load due to vehicle charging.In further embodiments, the power received from an electric utility maybe limited to power available during low-demand times, such as off-peakor low-priced periods of the day. One or more switches (not shown) atthe input ports 102 or 104 may be operable by the system controller 120to disconnect inflows of power during peak or high-priced periods of theday. In some embodiments, the rectifier 110 may be configured to enablepower reception during peak periods to ensure continued operation of theEV charging system 100 when power levels in the energy storage module114 are unexpectedly low.

In some embodiments, the power conversion module 112 may include one ormore DC-to-DC conversion circuits that receive DC current 128 at thefourth voltage (V₄) from the energy storage module 114 and drive acharging current 116 to a vehicle 140 through a vehicle coupling 132 tosupply a vehicle 140 with the charging current 116 at the second voltage(V₂) via a vehicle charge port 142. The vehicle coupling 132 serves asan electrical interconnect between the EV charging system 100 and thevehicle 140. In various embodiments, such vehicle coupling 132 comprisesa charging head and/or a charging cable. For example, the vehiclecoupling 132 may comprise a charging cable having a standard-compliantplug for connection with a vehicle charge port 142 of vehicles 140. Thevehicle coupling 132 may include both a power connection for carryingthe charging current 116 and a communication connection for carryingelectronic communication between the charge controller 130 and thevehicle 140. In some embodiments, the EV charging system 100 maycomprise multiple vehicle couplings 132, and the power conversion module112 may include a corresponding number of DC-to-DC conversion circuitsspecific to each of the multiple couplings. According to someembodiments, the power conversion module 112 may be further configuredto receive a reverse current 118 from a vehicle 140 via the vehiclecoupling 132, which reverse current 118 may be used to provide a DCenergy storage current 126 to add energy to the energy storage module114. In some embodiments, the power conversion module 112 includes oneor more inverters that convert the DC current 128 to an AC current thatcan be provided to various system components of the EV charging system100, such as the system components 138. In further embodiments, thepower conversion module 112 may further include one or more DC-to-DCconverters configured to provide a DC operating current to varioussystem components of the EV charging system 100, such as the systemcontroller 120 or the system components 138.

A charge controller 130 controls the charging current 116 and/or reversecurrent 118 through each vehicle coupling 132. To control charging ordischarging of the vehicle 140, the charge controller 130 comprises oneor more logic circuits (e.g., general or special-purpose processors)configured to execute charging control logic to manage charging sessionswith vehicle 140. Thus, the charge controller 130 is configured tocommunicate with the system controller 120 to control the powerconversion module 112 to provide the charging current 116 to the vehicle140 or to receive the reverse current 118 from the vehicle 140 via thevehicle coupling 132. In some instances, the charge controller 130 mayinclude power control circuits that further modify or control thevoltage level of the charging current 116 passed through the vehiclecoupling 132 to the vehicle 140. The charge controller 130 alsocommunicates via the vehicle coupling 132 with a vehicle chargecontroller 144 within the vehicle 140 to manage vehicle charging. Thus,the charge controller 130 communicates with the vehicle chargecontroller 144 to establish, control, and terminate charging sessionsaccording to EV charging protocols (e.g., CCS or CHaDEMO). The chargecontroller 130 may be communicatively connected with the vehiclecoupling 132 to provide output signals 134 to the vehicle chargecontroller 144 and to receive input signals 136 from the vehicle chargecontroller 144.

A system controller 120 is configured to control operations of the EVcharging system 100 by implementing control logic using one or moregeneral or special-purpose processors. The system controller 120 isconfigured to monitor and control power levels received by the rectifier110 from the power source, power levels provided from the rectifier 110to the power conversion module 112, power levels provided to the energystorage module 114 by the power conversion module 112, power levelsoutput through the charging current 116, and energy levels in the energystorage module 114. The system controller 120 is further configured tocommunicate with and control each of the one or more charge controllers130, as well as controlling the power conversion module 112. Forexample, the system controller 120 is configured to control the powerconversion module 112 and the charge controller to supply a chargingcurrent 116 to the vehicle coupling 132 in response to instructions fromthe charge controller 130. The system controller 120 is also configuredto control communication with the centralized management system 150 viacontrol of the communication interface module 124 and, in someembodiments, aspects of operation of the system controller 120 may becontrolled by commands received in electronic messages from thecentralized management system 150 via the communication interface module124.

The system controller 120 is also configured to communicate with othervarious system components 138 of the EV charging system 100 (e.g., othercontrollers or sensors coupled to the energy storage module 114 or othercomponents of the EV charging system 100) in order to receive operatingdata and to control operation of the system via operation of such systemcomponents 138. For example, the system components 138 may include aplurality of temperature control components (e.g., internal or externaltemperature sensors, coolant pumps, fans, or heater elements) configuredto maintain an internal temperature of the EV charging system 100 withinan operating range to avoid damage to or inefficient operation of thebatteries of the energy storage module 114. Thus, the system controller120 may monitor temperatures within the EV charging system 100 using thesystem components 138 and may be further configured to mitigateincreases in temperature through active cooling or power reductionsusing the same or different system components 138. Likewise, the systemcontroller 120 communicates with a user interface module 122 (e.g., atouchscreen display) and a communication interface module 124 (e.g., anetwork interface controller) to provide information and receive controlcommands. The communication interface module 124 may be configured tosend and receive electronic messages via wired or wireless dataconnections, which may include portions of one or more digitalcommunication networks.

The system controller 120 is configured to communicate with thecomponents of the EV charging system 100, including rectifier 110, powerconversion module 112, the user interface module 122, the communicationinterface module 124, the charge controller 130, and the systemcomponents 138 over one or more data communication links. The systemcontroller 120 may also be configured to communicate with externaldevices, including a vehicle 140 via the vehicle coupling 132, one ormore additional EV charging systems via the centralized managementsystem 150, or a site meter 22 (either directly or indirectly via alocal router 42 or via the centralized management system 150). Thesystem controller 120 may manage, implement or support one or more datacommunication protocols used to control communication over the variouscommunication links, including wireless communication or communicationvia a local router 42. The data communication protocols may be definedby industry standards bodies or may be proprietary protocols.

The user interface module 122 is configured to present informationrelated to the operation of the EV charging system 100 to a user and toreceive user input. The user interface module 122 may include or becoupled to a display with capabilities that reflect intended use of theEV charging system 100. In one example, a touchscreen may be provided topresent details of charging status and user instructions, includinginstructions describing the method of connecting and disconnecting avehicle 140. The user interface module 122 may include or be coupled toa touchscreen that interacts with the system controller 120 to provideadditional information or advertising. The system controller 120 mayinclude or be coupled to a wireless communication interface that can beused to deliver a wide variety of content to users of the EV chargingsystem 100, including advertisements, news, point-of-sale content forproducts/services that can be purchased through the user interfacemodule 122. The display system may be customized to match commercialbranding of the operator, to accommodate language options, or for otherpurposes. The user interface module 122 may include or be connected tovarious input components, including touchscreen displays, physical inputmechanisms, identity card readers, touchless credit card readers, andother components that interact through direct connections or wirelesscommunications. The user interface module 122 may further support userauthentication protocols and may include or be coupled to biometricinput devices such as fingerprint scanners, iris scanners, facialrecognition systems, or the like.

In some embodiments, the energy storage module 114 is provisioned with alarge battery pack, and the system controller 120 executes software tomanage input received from a power source to the battery pack based upondemand level data (e.g., demand or load data from an electric power grid20 or site meter 22), such that power is drawn from the power source tocharge the battery pack at low-load time periods and to avoid drawingpower from the grid during peak-load hours. The software may be furtherconfigured to manage power output to provide full, fast charging powerin accordance with usage data generated by monitoring patterns of usageby the EV charging system 100. The use of historical information canavoid situations in which the battery pack becomes fully discharged ordepleted beyond a minimum energy threshold. For example, charging may belimited at a first time based upon a predicted later demand at a secondtime, which later demand may be predicted using historical information.This may spread limited charging capacity more evenly among vehiclethroughout the course of a day or in other situations in which batterypack capacity is expected to be insufficient to fully charge all EVsover a time interval, taking account of the ability to add charge to theenergy storage module 114.

In further embodiments, the system controller 120 executes software(either separately or in coordination with the centralized managementsystem 150) to manage energy draw and use by controlling charging anddischarging over time among multiple EV charging systems 100 at thecharging site 10. Thus, the charge drawn from the power source may belimited or avoided during peak-load hours by using the charge previouslystored in the batteries of the energy storage module 114 to chargevehicles 140 and to provide operating current to the various systemcomponents (e.g., the system controller 120, the charge controller 130,the power conversion module 112, the user interface module 122, thecommunication interface module 124, and the system components 138)without drawing power from the power source (e.g., the electric powergrid 20). As noted above, in some embodiments, the charging site 10 mayinclude one or more external battery systems 30 connected to the localAC circuit 21, which may also supply power to the EV charging system 100without simultaneously drawing power from the power source (e.g., theelectric power grid 20). In such embodiments, the systems controller 120and/or the centralized management system 150 may further manage energyinflow and outflow of the EV charging system 100 by controllingselective charging and discharging of the batteries at appropriate timeperiods to avoid or reduce total power draw of the EV charging system100 from the power source during peak-demand or other high-demand timesby charging the batteries of the EV charging system 100 and any externalbattery systems 30 during low-demand times. In some embodiments, thesystem controller 120 or the centralized management system 150 mayreceive site data indicating total load at the charging site 10 from thesite meter 22 and thus control charging and discharging of the energystorage module 114 within site-wide limits during peak-demand or otherhigh-demand times.

In some embodiments, the EV charging system 100 may be configured withtwo or more vehicle couplings 132 to enable concurrent charging ofmultiple vehicles 140. The system controller 120 may be configured by auser via the user interface module 122 to support multiple modes ofoperation and may define procedures for charge transfer or powerdistribution that preserve energy levels in the energy storage module114 when multiple vehicles 140 are being concurrently charged. Chargetransfers may be used to transfer power from EV charging systems 100that have available power or are not being used to charge a vehicle 140to EV charging systems 100 that are charging one or more vehicles 140.Distribution of power may be configured to enable fast charging of oneor more vehicles 140 at the expense of other vehicles 140. In thisregard, the vehicle couplings 132 may be prioritized or the systemcontroller 120 may be capable of identifying and prioritizing connectedvehicles 140. In some instances, the system controller 120 may beconfigured to automatically control the respective charge controllers130 to split available power between two vehicles 140 after the secondvehicle 140 is connected. The available power may be evenly splitbetween two vehicles 140 or may be split according to priorities orcapabilities. In some examples, the system controller 120 may conductarbitration or negotiation between connected vehicles 140 to determine asplit of charging capacity. A vehicle 140 may request a charging powerlevel at any given moment based on temperature, battery charge level,and other characteristics of the vehicle 140 and its environment and toachieve maximum charge rate and minimum charging time for the currentcircumstances.

As illustrated, a vehicle 140 may be charged by connecting the vehicle140 to the EV charging system 100 via a vehicle coupling 132. This mayinclude plugging a charging cable of the EV charging system 100 into avehicle charge port 142 of the vehicle 140. The vehicle charge port 142is configured to receive the charging current 116 through the vehiclecoupling 132 and provide such received current to a vehicle powermanagement module 146. The vehicle charge port 142 is further configuredto provide an electronic communication connection between the vehiclecoupling 132 and a vehicle charge controller 144, which controlscharging of the vehicle 140. The vehicle power management module 146 iscontrolled by the vehicle charge controller 144 to provide power to eachof one or more batteries 148 of the vehicle 140 in order to charge suchbattery 148. In some instances, the vehicle charge port 142 includes alocking mechanism to engage and retain a portion of the vehicle coupling132 in place during charging sessions. For example, for safety reasons,the vehicle charge controller 144 may control a locking mechanism of thevehicle charge port 142 to lock a plug of a charging cable in thevehicle charge port 142 while a charging session is active.

The EV charging system 100 also includes a resilient power subsystem 180to enable resilient operation of the EV charging system 100 during timeintervals in which power is not being drawn from the external powersource (e.g., when the EV charging system 100 is disconnected from theelectric power grid 20, when the electric power grid 20 is experiencinga grid failure, or when the system controller 120 prevents the EVcharging system 100 from drawing power from the electric power grid 20due to high demand on the grid or otherwise). The resilient powersubsystem 180 is configured to provide an operating current to thevarious system components required for continued operation of the EVcharging system 100 derived from the charge stored in one or morebatteries of the energy storage module 114, rather than providing theoperating current derived from an input power received from an externalpower source at input port 102 or 104. The operating current provided bythe resilient power subsystem 180 is a DC operating current at the thirdvoltage (V₃) at which the system components operate. For example, thesystem controller 120, user interface module 122, communicationinterface module 124, charge controller 130, and other system components138 may be configured to operate using a 24V DC operating current. Insome embodiments, more than one operating currents may need to besupplied to the various system components, in which case a plurality ofpower conversion circuits (e.g., a plurality of step-down converters113) within the power conversion module 112 may be used to providemultiple operating currents at difference voltages. For example, thesystem controller 120 may require a 1.2V DC operating current, whiletemperature control components of the system components 138 may requirea 24V DC or 110V AC operating current. Thus, the multiple operatingcurrents may be provided to different system components.

The resilient power subsystem 180 comprises at least some elements ofthe power conversion module 112, the energy storage module 114, thesystem controller 120, and a DC bus 160. The power conversion module 112is configured with one or more resilient power conversion circuits toreceive a DC current from the energy storage module 114 at the fourthvoltage (V₄) and convert it into a DC operating current at the thirdvoltage (V₃), which is less than the second voltage (V₂) of the chargingcurrent 116. Such resilient power conversion circuits may comprisestep-down converters, step-up converters, or buck-boost convertersconfigured to produce the DC operating current at the desired voltagefrom the DC current 128. In some embodiments, the power conversionmodule 112 particularly comprises a step-down converter 113 configuredspecifically to produce the DC operating current at the third voltage(V₃) from the DC current 128 at the fourth voltage (V₄) from one or morebatteries of the energy storage module 114. In embodiments in whichmultiple DC operating currents at different voltages are provided todifferent system components, the power conversion module 112 may includea plurality of such step-down converters 113 to provide the DC operatingcurrents at the different voltages. As noted above, the resilient powersubsystem 180 may include a backup battery 115 of the energy storagemodule 114, which backup battery 115 may store a charge at a lowervoltage than the other batteries of the energy storage module 114 inorder to better match the voltage requirements of the system components.In some embodiments, the DC operating current is provided to the varioussystem components (e.g., the system controller 120, the user interfacemodule 122, the communication interface module 124, the chargecontroller 130, and the system components 138) via a DC bus 160 thatreceives the DC operating current from the power conversion module 112.In embodiments in which multiple operating currents at differentvoltages are provided to different system components, a plurality of DCbusses 160 may be used to provide the various operating currents.

As illustrated, the resilient power subsystem 180 may comprise acombination of components within the EV charging system 100 that performadditional functions not limited to ensuring resilient operation byproviding an operating current derived from charge stored in one or morebatteries of the energy storage module 114. In some embodiments,however, the resilient power subsystem 180 may be composed of a set ofcomponents, modules, and connections that are distinct from or separatefrom those of a primary power subsystem that provides the operatingcurrent derived from an input power received from the power sourceduring times when the input power is being received from the powersource. Thus, in some embodiments, the system controller 120 may beconfigured to control the provision of operating current to other systemcomponents within the EV charging system 100, both during a primaryoperating mode while power is being received from the power source andduring a resilient operating mode while power is not being received fromthe power source. Controlling the EV charging system 100 in a primaryoperating mode may comprise causing the primary power subsystem toprovide the operating current to the system components during a timeinterval in which an input electric power is being received at inputport 102 or 104 from an external power source. The primary power systemderives the operating current from the input electric power receivedfrom the power source. For example, in the primary operating mode, a DCoperating current may be provided to the various system components fromthe rectifier 110 via the DC bus 160. Controlling the EV charging system100 in a resilient operating mode may comprise causing the resilientpower subsystem 180 to derive the operating current from a charge storedin one or more batteries of the energy storage module 114 and providethe operating current to the various system components. For example, thestep-down converter 113 of the power conversion module 112 may provide aDC operating current to the various system components via the DC bus 160in the resilient operating mode. A plurality of switches (not shown) maybe disposed within the EV charging system 100 to enable the systemcontroller 120 to control operation of the system in either the primaryoperating mode or the resilient operating mode.

FIG. 2B illustrates a block diagram of an alternative example of the EVcharging system 100 configured in accordance with certain aspectsdisclosed herein. While otherwise the same as the EV charging system 100of FIG. 2A, the EV charging system 100 of FIG. 2B includes analternative embodiment of the resilient power subsystem 182 thatprovides an AC operating current at a third voltage (V₃) to at leastsome of the system components (e.g., system components 138), whichincludes a bidirectional inverter 111 that replaces the rectifier 110.Providing an AC operating current may be desirable in order to utilizeAC system components that operate more efficiently in the primaryoperating mode. Since the EV charging system 100 is expected to bepowered by an external power source during ordinary conditions, it maybe preferable to use some system components configured to receive an ACoperating current, even it such configuration is less efficient whenoperating in the resilient operating mode.

The resilient power subsystem 182 comprises a bidirectional inverter111, a power conversion modules 112, an energy storage module 114, asystem controller 120, and an AC bus 170. In some embodiments, theresilient power subsystem 182 further comprises a rectifier 172 toprovide a DC controller operating current to the system controller 120,such that the DC controller operating current is derived from the ACoperating current produced by the bidirectional inverter 111 from thecharge stored in one or more batteries of the energy storage module 114.Alternatively, the power conversion module 112 (or a step-down converter113 thereof) may provide the DC controller operating current to thesystem controller 120. Additional or alternative components andfunctionality may be included in further alternative embodiments ofcharging systems.

The bidirectional inverter 111 is configured to alternatively operate inan inverter mode or in a rectifier mode at various times as controlledby the system controller 120. In the rectifier mode, the bidirectionalinverter 111 converts an AC input electric power current from a powersource (e.g., the electric power grid 20) into a DC input current toprovide to the energy storage module 114 via the power conversion module112. In the inverter mode, the bidirectional inverter 111 converts a DCoutput current from one or more batteries of the energy storage module114 (e.g., backup battery 115) via the power conversion module 112 intoan AC operating current at the third voltage (V₃) to provide to ACsystem components via the AC bus 170. Thus, when a triggering conditionoccurs to cause the EV charging system 100 to provide the AC operatingcurrent to the system components, the system controller 120 controls thebidirectional inverter 111 to operate in the inverter mode to convert aDC current received from one or more batteries of the energy storagemodule 114 into an AC current that is provided to the AC bus 170. Insome embodiments, a plurality of separate components may instead beconfigured to perform such functionality of the bidirectional inverter111, such as by retaining the rectifier 110 and adding a separateinverter 174 (as illustrated in the resilient power subsystem 184 ofFIG. 2C). In further embodiments, part or all of the functionality ofthe bidirectional inverter 111 may be incorporated into the powerconversion module 112, or part or all of the functionality of the powerconversion module 112 may be incorporated into the bidirectionalinverter 111. In some embodiments, multiple bidirectional inverters 111may be used or the bidirectional inverter 111 may include circuits toprovide multiple AC operating currents having different voltagesrequired by different system components.

In addition to providing the AC operating current to the AC systemcomponents, in some embodiments, the bidirectional inverter 111 mayfurther provide an AC output current at the input port 102, which may beprovided to other EV charging systems 100A-D or a non-charging load 24at the charging site 10 via the local AC circuit 21. For example, one EVcharging system 100A may provide the AC output current via local ACcircuit 21 to the other EV charging systems 100B-D, thus enablingoperation of such other EV charging systems 100B-D without the need forinternal generation of AC operating current from their respective energystorage modules 114B-D. Such an arrangement may be used to improveefficiency at charging sites 10 having multiple EV charging systems100A-D.

The AC bus 170 is configured to provide the AC operating current tovarious system components within the EV charging system 100, such assystem components 138 configured to operate using an AC current. As withthe DC bus 160, multiple AC busses 170 may be included in embodiments inwhich multiple AC operating currents are provided at different voltages.The AC bus 170 may further provide the AC operating current to arectifier 172 in order to provide a DC operating current to the systemcontroller 120 or other DC system components. For example, the rectifier172 may be configured to convert the AC operating current into a DCcontroller operating current used by the system controller 120 and/orthe charge controller 130. In further embodiments, the step-downconverter 113 or other circuits of the power conversion module 112 mayprovide the DC controller operation current to the controller. Invarious embodiments, the rectifier 172 (or power conversion module 112)may provide the DC operating current to additional DC system components,or the system controller 120 may provide a DC operating current to otherDC system components.

FIG. 2C illustrates a block diagram of another alternative example ofthe EV charging system 100 configured in accordance with certain aspectsdisclosed herein. While otherwise the same as the EV charging system 100of FIGS. 2A-B, the EV charging system 100 of FIG. 2C includes analternative embodiment of the resilient power subsystem 184 thatprovides an AC operating current at a third voltage (V₃) to at leastsome of the system components (e.g., system components 138), using aninverter 174 that is separate from the rectifier 110. The rectifier 110receives the AC input electric power from the power source at input port102 and provides the DC input current to the power conversion module112, which is then used to charge the batteries of the energy storagemodule 114. The inverter 174 is later used to provide the AC operatingcurrent from the charge stored in one or more batteries of the energystorage module 114.

The resilient power subsystem 184 comprises a rectifier 110, a powerconversion modules 112, an energy storage module 114, a systemcontroller 120, and an inverter 174. In some embodiments, the resilientpower subsystem 184 further comprises an AC step-down converter 176(e.g., a transformer) to provide the AC operating current at the thirdvoltage (V₃) to the AC system components (e.g., one or more systemcomponents 138 configured to operate using an AC current). The rectifier110 also receive the AC current provided from the inverter 174, thusenabling the rectifier to operate the same in both a primary operatingmode and a resilient operating mode to provide the DC operating current.In the resilient operating mode, however, the power conversion module112 prevents charging the batteries of the energy storage module 114using the DC input current provided by the rectifier 110. Additional oralternative components and functionality may be included in furtheralternative embodiments of charging systems.

The inverter 174 is configured to receive a DC output current from oneor more batteries of the energy storage module 114 (e.g., backup battery115), either directly or from the power conversion module 112. Theinverter 174 converts such DC output current into an AC current andprovides such AC current to an electrical connection between the inputport 102 and the rectifier 110. Such AC current may be an AC resilientpower current provided at the first voltage (V₁) equivalent to that ofthe AC input electric power from the power source. In some embodiments,the AC system components are configured to operate using the AC inputelectric power at the first voltage (V₁) from the power source, suchthat the AC operating current at the at the third voltage (V₃) isequivalent to the AC input electric power at the first voltage (V₁). Insuch embodiments, such system components receive the AC operatingcurrent at the at the third voltage (V₃) from the inverter 174. Althoughnot shown, one or more AC busses similar to the AC bus 170 may beincluded to provide the AC operating power.

In some embodiments, an AC step-down converter 176 is provided betweenthe input port 102 and the AC system components (e.g., system components138). Such step-down converter may be configured to receive (i) the ACresilient power current at the first voltage (V₁) and convert it intothe AC operating current at the third voltage (V₃) during time intervalsin which the AC input electric power is not being received from thepower source and (ii) receive the AC input electric power at the firstvoltage (V₁) and convert it into the AC operating current at the thirdvoltage (V₃) during other time intervals in which the AC input electricpower is being received from the power source. Thus, the AC step-downconverter 176 operates as a primary power subsystem to provide the ACoperating current to the AC system components when the EV chargingsystem 100 is operating in the primary operating mode and as a part ofthe resilient power subsystem 184 when the EV charging system 100 isoperating in the resilient operating mode.

The rectifier 110 also receives the AC current from the inverter 174 andconverts the AC current from the inverter 174 into a DC operatingcurrent, such as the controller operating current provided to the systemcontroller 120, such that the DC operating current is derived from theAC current produced by the inverter 174 from the charge stored in one ormore batteries of the energy storage module 114. Alternatively, thepower conversion module 112 (or a step-down converter 113 thereof) mayprovide the DC controller operating current to the system controller120. In various embodiments, the rectifier 110 (or power conversionmodule 112) may provide the DC operating current to additional DC systemcomponents, or the system controller 120 may provide a DC operatingcurrent to other DC system components.

Exemplary Methods for Resilient Operation of Charging Systems

FIG. 3 illustrates a flow diagram of an example resilient chargingmethod 300 for operating a resilient charging system to continue vehiclecharging despite disconnection from or failure of a power source inaccordance with certain aspects disclosed herein. The resilient chargingsystem may be any of the EV charging systems 100 described herein orother similar EV charging systems configured to power internal systemcomponents from one or more batteries used to provide a charging currentto vehicles in a resilient operating mode while the EV charging systemsare not obtaining an AC input electric power from an external powersource. The resilient charging method 300 may be implemented by a systemcontroller 120 of an EV charging system 100 controlling operation of aresilient power subsystem 180, 182, or 184 of the EV charging system100.

The example resilient charging method 300 provides power to systemcomponents of an EV charging system in two modes. Blocks 302-310represent operation in a primary operating mode of the EV chargingsystem during which an input electric power is being received from apower source external to the EV charging system. At decision block 312,it is determined whether the power source is available to supply theinput electric power. When the power source is not available, the EVcharging system operates in a resilient operating mode to provide powerderived from one or more batteries of the EV charging system to thesystem components while the input electric power is not being receivedfrom the power source. The resilient charging method 300 begins withcharging one or more batteries of the EV charging system using an inputelectric power from the power source (block 302). The input electricpower is further used to provide a controller operating current to thesystem controller of the EV charging system (block 304) and to providean operating current to other system components of the EV chargingsystem (block 306). When a vehicle is present to charge, the EV chargingsystem further provides a charging current derived from the chargestored in its one or more batteries to the vehicle (block 308). The EVcharging system further monitors the availability of the power supply(block 310) in order to determine whether the power supply is available(block 312). If the power supply continues to be available, the method300 continues charging the batteries at block 302. If the power supplyis not available, the EV charging system switches from the primaryoperating mode to the resilient operating mode and provides a controlleroperating current derived from the one or more batteries of the EVcharging system to the system controller (block 314). The chargepreviously stored in the one or more batteries is further used toprovide an operating current to the other system components (block 316).Powering the various system components in the resilient operating modefurther enables the EV charging system to provide a charging current toa vehicle during a time when the input electric power is not beingreceived from the power source (block 318). Additional or alternativeaspects may be included in some embodiments.

At block 302, the EV charging system 100 receives an input electricpower from an external power source (e.g., AC power from the electricpower grid 20). As discussed above, the input electric power isconverted by one or more of a rectifier 110 or bidirectional inverter111 and a power conversion module 112, then provided to the energystorage module 114 to charge the one or more batteries of the energystorage module 114. In some embodiments, the power source provides an ACor DC input electric power at a lower first voltage (V₁) than a secondvoltage (V₂) of the output charging current used to charge vehicles 140.Therefore, charging the batteries of the EV charging systems may occurslowly over a substantially longer time than discharging occurs. Asnoted above, the system controller 120 may control provision of the DCcurrent 126 to the energy storage module 114, which may include a backupbattery 115.

At block 304, the EV charging system 100 provides a controller operatingcurrent to the system controller 120 in the primary operating modeduring a time interval in which the input electric power is beingreceived by the EV charging system from the power source. In someembodiments, the controller operating current is provided as a DCoperating current at a third voltage (V₃) to the system controller 120by a primary power subsystem of the EV charging system 100 configured toprovide a DC operating current derived from the input electric powerreceived from the power source when operating in the primary operatingmode. Thus, in some embodiments, the system controller 120 receives theDC operating current from the rectifier 110 (either directly or via DCbus 160) or from the rectifier 172, each of which receives the AC inputelectric power from the power source at input port 102 while operatingin the primary operating mode.

At block 306, the EV charging system 100 provides an operating currentto the system components 138 (and, in some embodiments, to other systemcomponents) in the primary operating mode during the time interval inwhich the input electric power is being received by the EV chargingsystem from the power source. The operating current may include an ACoperating current and/or a DC operating current at a third voltage (V₃),according to various embodiments described herein. In some embodiments,the operating current is provided to the system components (e.g., systemcomponents 138) by a primary power subsystem of the EV charging system100 configured to provide an operating current derived from the inputelectric power received from the power source when operating in theprimary operating mode. Thus, in some embodiments, the system components138 receive a DC operating current from a DC bus 160 supplied with theDC operating current from the rectifier 110 of the primary powersubsystem, which converts the AC input electric power received from thepower source at input port 102 into the DC operating current whileoperating in the primary operating mode. In further embodiments, thesystem components 138 receive an AC operating current from an AC bus 170or an AC step-down converter 176 of the primary power subsystem, whichis connected to the input port 102 to receive the AC input electricpower from the power source while operating in the primary operatingmode.

At block 308, in some instances, the EV charging system 100 provides acharging current 116 at the second voltage (V₂) to a vehicle 140 acoupling 132 during the time interval in which the input electric poweris being received by the EV charging system from the power source. Tocharge the vehicle 140, the system controller 120 causes the powerconversion module 112 (either directly or indirectly) to receive the DCcurrent 128 from one or more batteries of the energy storage module 114and provide the charging current 116 to the coupling 132. The chargecontroller 130 controls provision of the charging current 116 to thevehicle charge port 142 of the vehicle 140. Operation of the chargecontroller 130 may be controlled by the system controller 120. Invarious embodiments, both the system controller 120 and the chargecontroller 130 receive the DC controller operating current provided bythe primary power subsystem as described above, either directly orindirectly. For example, the charge controller 130 may receive the DCcontroller operating current from the system controller 120.

At block 310, the system controller 120 of the EV charging system 100monitors the power supply to determine availability of the power supply.In some embodiments, the system controller 120 may detect power sourceavailability based upon sensor data received from one or more sensorsdisposed within the EV charging system 100. For example, the systemcontroller 120 may detect the power source is unavailable by detectingno power is being received (e.g., no voltage is detected) at any inputports 102 or 104 using one or more sensors. In further embodiments, thesystem controller 120 may obtain power source data regarding the powersource from the site meter 22 or the centralized management system 150.Such power source data may include an indication of whether the powersource is available (e.g., whether the electric power grid 20 isconnected and powered to provide electric power to the charging site10), or such power source data may further include demand data regardingload on or demand charges for the power source.

At block 312, the system controller 120 determines whether the powersource is available. In some embodiments, determining whether the powersource is available may comprise determining whether a triggeringcondition associated with power source unavailability has occurred.Determining occurrence of such triggering condition may comprisedetecting the EV charging system 100 is not receiving an input electricpower from the power source at the time of the triggering condition(e.g., the electric power grid 20 is down or disconnected). In someembodiments, occurrence of the triggering condition may be determinedbased upon the power source data regarding the power source. In someembodiments, the centralized management system 150 determines occurrenceof a triggering condition, then sends a command to one or more of the EVcharging systems in an electronic message to the EV charging system 100to cause the EV charging system 100 to enter a resilient operating mode.In various embodiments, occurrence of the triggering condition mayinclude detection of disconnection of the power source from the EVcharging system 100, or determining occurrence of the triggeringcondition may include determining a demand level for the power sourceexceeds a threshold demand level (e.g., determining the load or demandcharges of the electric power grid 20 exceeding thresholds associatedwith high demand relative to supply of power to the grid). If suchdemand level is determined to exceed the threshold demand level, thesystem controller 120 may control the EV charging system 100 to stopdrawing the input electrical power from the power source (e.g., byoperating a switch within the EV charging system 100 or the site meter22 to disconnect from the power source). An indication of such demandlevel or an indication that the demand level exceeds to the thresholddemand level may be received from the site meter 22, from a server orcontroller associated with the power source, or from the centralizedmanagement system 150.

When the system controller 120 determines the power source is available(e.g., determines that no triggering event indicating unavailability hasoccurred), the system controller 120 causes the EV charging system 100to continue to operate in the primary operating mode at block 302, inwhich primary operating mode the EV charging system 100 continues todraw the input electric power from the power source. When the systemcontroller 120 determines the power source is not available (e.g.,determines that a triggering event indicating unavailability hasoccurred), the system controller 120 causes the EV charging system 100to operate instead in the resilient operating mode, in which resilientoperating mode the EV charging system 100 does not draw an inputelectric power from the power source. To begin or continue operating inthe resilient operating mode, the system controller 120 controls theresilient power subsystem 180, 182, or 184 to provide one or moreoperating currents derived from a charge stored in one or more batteriesof the energy storage module 114 to the system components (e.g., byproviding a controller operating current to the system controller 120and an AC or DC operating current to other system components 138).

At block 314, the system controller 120 causes the resilient powersubsystem 180, 182, or 184 to produce and provide a controller operatingcurrent at the third voltage (V₃) derived from a charge stored in one ormore batteries of the energy storage module 114 to the system controller120 during the time interval in which the input electric power is notbeing received by the EV charging system from the power source. In someembodiments, the resilient power subsystem 180, 182, or 184 produces andprovides the DC controller operating current to the system controller120 by providing a DC operating current to a DC bus 160 using astep-down converter 113 or other conversion circuits of the powerconversion module 112 to convert a DC current 128 received from one ormore batteries of the energy storage module 114 (which may include abackup battery 115). In further embodiments, the resilient powersubsystem 182 produces and provides the DC controller operating currentto the system controller 120 by providing an AC operating current to anAC bus 170 using a bidirectional inverter 111 to convert a DC current128 received from one or more batteries of the energy storage module 114(which may include a backup battery 115) via the power conversion module112 into the AC operating current, then using a rectifier 172 to convertthe AC operating current to the DC controller operating current providedto the system controller 120. In yet further embodiments, the resilientpower subsystem 184 produces and provides the DC controller operatingcurrent to the system controller 120 by providing an AC resilient powercurrent to an input port 102 using an inverter 174 to convert a DCcurrent received from one or more batteries of the energy storage module114 (which may include a backup battery 115) into the AC resilient powercurrent, from which AC resilient power current a rectifier 110 thenproduces and provides the DC controller operating current to the systemcontroller 120.

At block 316, the system controller 120 causes the resilient powersubsystem 180, 182, or 184 to produce and provide an operating currentat the third voltage (V₃) derived from a charge stored in one or morebatteries of the energy storage module 114 to the system components 138(and, in some embodiments, to other system components) during the timeinterval in which the input electric power is not being received by theEV charging system from the power source. The operating current mayinclude an AC operating current and/or a DC operating current, accordingto various embodiments described herein. In some embodiments, theresilient power subsystem 180, 182, or 184 produces and provides a DCoperating current to the system components 138 by providing a DCoperating current to a DC bus 160 using a step-down converter 113 orother conversion circuits of the power conversion module 112 to converta DC current 128 received from one or more batteries of the energystorage module 114 (which may include a backup battery 115). In furtherembodiments, the resilient power subsystem 182 produces and provides anAC operating current to the system components 138 (and, in someembodiments, to other system components) via an AC bus 170 by using abidirectional inverter 111 to convert a DC current 128 received from oneor more batteries of the energy storage module 114 (which may include abackup battery 115) via the power conversion module 112 into the ACoperation current. In yet further embodiments, the resilient powersubsystem 184 produces and provides an AC operating current to thesystem components 138 (and, in some embodiments, to other systemcomponents) by providing an AC resilient power current to an input port102 using an inverter 174 to convert a DC current received from one ormore batteries of the energy storage module 114 (which may include abackup battery 115) into the AC resilient power current. In some suchembodiments, the AC resilient power current may be the AC operatingcurrent. In alternative such embodiments, the AC operating current isderived from the AC resilient power current by an AC step-down converter176 that produces and provides the AC operating current to the systemcomponents 138 from the AC resilient power current. In some embodiments,combinations of the resilient power subsystems 180, 182, or 184 may beused to provide both AC and DC operating currents to different systemcomponents of the EV charging system 100.

At block 318, in some instances, the EV charging system 100 provides acharging current 116 at the second voltage (V₂) to a vehicle 140 acoupling 132 during the time interval in which the input electric poweris not being received by the EV charging system from the power source.To charge the vehicle 140, the system controller 120 causes the powerconversion module 112 (either directly or indirectly) to receive the DCcurrent 128 from one or more batteries of the energy storage module 114and provide the charging current 116 to the coupling 132. The chargecontroller 130 controls provision of the charging current 116 to thevehicle charge port 142 of the vehicle 140. Operation of the chargecontroller 130 may be controlled by the system controller 120. Invarious embodiments, both the system controller 120 and the chargecontroller 130 receive the DC controller operating current provided bythe resilient power subsystem 180, 182, or 184 as described above,either directly or indirectly. For example, the charge controller 130may receive the DC controller operating current from the systemcontroller 120.

Additional Description Related to Controllers

FIG. 4 illustrates a block diagram illustrating a simplified example ofa hardware implementation of a controller 400, such as any of the systemcontroller 120, the charge controller 130, the vehicle charge controller144, or the centralized management system 150 disclosed herein. In someembodiments, the controller 400 may be a controller of a site meter 22,an external battery system 30, or any other component disclosed hereinthat implements control logic to control any aspect of the describedsystems and methods. The controller 400 may include one or moreprocessors 404 that are controlled by some combination of hardware andsoftware modules. Examples of processors 404 include microprocessors,microcontrollers, digital signal processors (DSPs), application-specificintegrated circuits (ASICs), field programmable gate arrays (FPGAs),programmable logic devices (PLDs), state machines, sequencers, gatedlogic, discrete hardware circuits, and other suitable hardwareconfigured to perform the various functionality described throughoutthis disclosure. The one or more processors 404 may include specializedprocessors that perform specific functions, which may be configured byone or more of the software modules 416. The one or more processors 404may be configured through a combination of software modules 416 loadedduring initialization and may be further configured by loading orunloading one or more software modules 416 during operation.

In the illustrated example, the controller 400 may be implemented with abus architecture, represented generally by the bus 410. The bus 410 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the controller 400 and the overall designconstraints. The bus 410 links together various circuits including theone or more processors 404 and storage 406. Storage 406 may includememory devices and mass storage devices, any of which may be referred toherein as computer-readable media. The bus 410 may also link variousother circuits, such as timing sources, timers, peripherals, voltageregulators, and power management circuits. A bus interface 408 mayprovide an interface between the bus 410 and one or more line interfacecircuits 412, which may include a line interface transceiver circuit 412a and a radio frequency (RF) transceiver circuit 412 b. A line interfacetransceiver circuit 412 a may be provided for each networking technologysupported by the controller. In some instances, multiple networkingtechnologies may share some or all of the circuitry or processingmodules found in a line interface circuit 412, such as line interfacetransceiver circuit 412 a for wired communication and RF transceivercircuit 412 b for wireless communication. Each line interface circuit412 provides a means for communicating with various other devices over atransmission medium. In some embodiments, a user interface 418 (e.g.,touchscreen display, keypad, speaker, or microphone) may also beprovided, and may be communicatively coupled to the bus 410 directly orthrough the bus interface 408.

A processor 404 may be responsible for managing the bus 410 and forgeneral processing that may include the execution of software stored ina computer-readable medium that may include the storage 406. In thisrespect, the processor 404 of the controller 400 may be used toimplement any of the methods, functions, and techniques disclosedherein. The storage 406 may be used for storing data that is manipulatedby the processor 404 when executing software, and the software may beconfigured to implement any of the methods disclosed herein.

One or more processors 404 in the controller 400 may execute software.Software may include instructions, instruction sets, code, codesegments, program code, programs, subprograms, software modules,applications, software applications, software packages, routines,subroutines, objects, executables, threads of execution, procedures,functions, algorithms, etc., whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise. Thesoftware may reside in computer-readable form in the storage 406 or inan external computer readable medium. The external computer-readablemedium and/or storage 406 may include a non-transitory computer-readablemedium. A non-transitory computer-readable medium includes, by way ofexample, a magnetic storage device (e.g., hard disk, floppy disk,magnetic strip), an optical disk, a smart card, a flash memory device(e.g., a “flash drive,” a card, a stick, or a key drive), a randomaccess memory (RAM), a read only memory (ROM), a programmable ROM(PROM), an erasable PROM (EPROM), an electrically erasable PROM(EEPROM), a register, a removable disk, and any other suitable mediumfor storing software and/or instructions that may be accessed and readby a computer. Portions of the computer-readable medium or the storage406 may reside in the controller 400 or external to the controller 400.The computer-readable medium and/or storage 406 may be embodied in acomputer program product. By way of example, a computer program productmay include a non-transitory computer-readable medium in packagingmaterials. Those skilled in the art will recognize how best to implementthe described functionality presented throughout this disclosuredepending on the particular application and the overall designconstraints imposed on the overall system.

The storage 406 may maintain software maintained or organized inloadable code segments, modules, applications, programs, etc., which maybe referred to herein as software modules 416. Each of the softwaremodules 416 may include instructions and data that, when installed orloaded on the controller 400 and executed by the one or more processors404, contribute to a run-time image 414 that controls the operation ofthe one or more processors 404. When executed, certain instructions maycause the controller 400 to perform functions in accordance with certainmethods, algorithms, and processes described herein.

Some of the software modules 416 may be loaded during initialization ofthe controller 400, and these software modules 416 may configure thecontroller 400 to enable performance of the various functions disclosedherein. For example, some software modules 416 may configure internaldevices or logic circuits 422 of the processor 404, and may manageaccess to external devices such as line interface circuits 412, the businterface 408, the user interface 418, timers, mathematicalcoprocessors, etc. The software modules 416 may include a controlprogram or an operating system that interacts with interrupt handlersand device drivers to control access to various resources provided bythe controller 400. The resources may include memory, processing time,access to the line interface circuits 412, the user interface 418, etc.

One or more processors 404 of the controller 400 may be multifunctional,whereby some of the software modules 416 are loaded and configured toperform different functions or different instances of the same function.For example, the one or more processors 404 may additionally be adaptedto manage background tasks initiated in response to inputs from the userinterface 418, the line interface circuits 412, and device drivers. Tosupport the performance of multiple functions, the one or moreprocessors 404 may be configured to provide a multitasking environment,whereby each of a plurality of functions is implemented as a set oftasks serviced by the one or more processors 404 as needed or desired.In one example, the multitasking environment may be implemented using atimesharing program 420 that passes control of a processor 404 betweendifferent tasks, whereby each task returns control of the one or moreprocessors 404 to the timesharing program 420 upon completion of anyoutstanding operations or in response to an input such as an interrupt.When a task has control of the one or more processors 404, theprocessing circuit is effectively specialized for the purposes addressedby the function associated with the controlling task. The timesharingprogram 420 may include an operating system, a main loop that transferscontrol on a round-robin basis, a function that allocates control of theone or more processors 404 in accordance with a prioritization of thefunctions, or an interrupt-driven main loop that responds to externalevents by providing control of the one or more processors 404 to ahandling function.

OTHER CONSIDERATIONS

Although the preceding text sets forth a detailed description ofnumerous different embodiments, it should be understood that the legalscope of the invention is defined by the words of the claims set forthat the end of this patent. The detailed description is to be construedas exemplary only and does not describe every possible embodiment, asdescribing every possible embodiment would be impractical, if notimpossible. One could implement numerous alternate embodiments, usingeither current technology or technology developed after the filing dateof this patent, which would still fall within the scope of the claims.

It should also be understood that, unless a term is expressly defined inthis patent using the sentence “As used herein, the term ‘______’ ishereby defined to mean . . . ” or a similar sentence, there is no intentto limit the meaning of that term, either expressly or by implication,beyond its plain or ordinary meaning, and such term should not beinterpreted to be limited in scope based upon any statement made in anysection of this patent (other than the language of the claims). To theextent that any term recited in the claims at the end of this patent isreferred to in this patent in a manner consistent with a single meaning,that is done for sake of clarity only so as to not confuse the reader,and it is not intended that such claim term be limited, by implicationor otherwise, to that single meaning. No claim element is to beconstrued as a means plus function unless the element is expresslyrecited using the phrase “means for.”

Throughout this specification, plural instances may implementcomponents, operations, or structures described as a single instance.Although individual operations of one or more methods are illustratedand described as separate operations, one or more of the individualoperations may be performed concurrently, and nothing requires that theoperations be performed in the order illustrated. Structures andfunctionality presented as separate components in example configurationsmay be implemented as a combined structure or component. Similarly,structures and functionality presented as a single component may beimplemented as separate components. These and other variations,modifications, additions, and improvements fall within the scope of thesubject matter herein. Unless specifically stated otherwise, the term“some” refers to one or more. Likewise, use of the “a” or “an” areemployed to describe elements and components of the embodiments herein.This is done merely for convenience and to give a general sense of thedescription. This description, and the claims that follow, should beread to include one or at least one and the singular also includes theplural unless the context clearly indicates otherwise.

Upon reading this disclosure, those of skill in the art will appreciatestill additional alternative structural and functional designs for thesystems and a methods disclosed herein. Thus, while particularembodiments and applications have been illustrated and described, it isto be understood that the disclosed embodiments are not limited to theprecise construction and components disclosed herein. Variousmodifications, changes and variations, which will be apparent to thoseskilled in the art, may be made in the arrangement, operation anddetails of the method and apparatus disclosed herein without departingfrom the spirit and scope defined in the appended claims.

What is claimed is:
 1. A vehicle charging system for charging a vehicle,comprising: a power input port configured to receive input electricpower from a power source at a first voltage (V₁); a plurality ofbatteries configured to receive a direct current (DC) input currentderived from the input electric power received at the power input portand store electric power from the DC input current; a vehicle couplingconfigured to receive a DC charging current at a second voltage (V₂)derived from the plurality of batteries and to provide an electricalinterconnect between the vehicle charging system and the vehicle inorder to provide the DC charging current to the vehicle; a resilientpower subsystem configured to provide a DC operating current at a thirdvoltage (V₃) derived from electric power stored in at least one of theplurality of batteries to a plurality of system components within thevehicle charging system, wherein the system components are configured tocontrol operation of the vehicle charging system; and a systemcontroller of the plurality of system components, the system controllercomprising one or more processors configured to: receive the DCoperating current during a time interval in which the input electricpower is not being received from the power source; and control thevehicle charging system to provide the DC charging current to theelectrical interconnect to charge the vehicle during the time interval.2. The vehicle charging system of claim 1, wherein: the input electricpower is an alternating current (AC) input electric power received froman electric power grid; and the vehicle charging system furthercomprises a rectifier configured to receive the AC input electric powerand provide the DC input current to the plurality of batteries.
 3. Thevehicle charging system of claim 1, wherein: each of the plurality ofbatteries stores the electric power at a fourth voltage (V₄); and thesecond, third, and fourth voltages satisfy the following criteria:V₃<V₄<V₂.
 4. The vehicle charging system of claim 3, wherein theresilient power subsystem comprises a step-down converter configured toreceive a battery current from the at least one of the plurality ofbatteries at the fourth voltage (V₄) and provide the DC operatingcurrent at the third voltage (V₃) to the plurality of system components.5. The vehicle charging system of claim 1, wherein the resilient powersubsystem comprises a DC bus configured to provide the DC operatingcurrent to the plurality of system components.
 6. The vehicle chargingsystem of claim 1, wherein the plurality of system components furthercomprise a plurality of temperature control components configured tomaintain an internal temperature of the vehicle charging system withinan operating range.
 7. The vehicle charging system of claim 1, wherein:the resilient power subsystem is further configured to provide the DCoperating current to the plurality of system components during a secondtime interval in which the input electric power is being received fromthe power source; and the one or more processors of the systemcontroller are further configured to: receive the DC operating currentfrom the resilient power subsystem during the second time interval; andcontrol the vehicle charging system to provide the DC charging currentto the electrical interconnect to charge the vehicle during the secondtime interval.
 8. The vehicle charging system of claim 1, furthercomprising a primary power subsystem configured to provide the DCoperating current to the plurality of system components during a secondtime interval in which the input electric power is being received fromthe power source, wherein the one or more processors of the systemcontroller are further configured to: receive the DC operating currentfrom the primary power subsystem during the second time interval; detecta triggering condition indicating the input electric power is not beingreceived from the power source at the beginning of the time interval;and cause the resilient power subsystem to begin providing the DCoperating current during the time interval in response to detecting thetriggering condition.
 9. A method for charging a vehicle by a vehiclecharging system, comprising: receiving, at a power input port of thevehicle charging system, an input electric power from a power source ata first voltage (V₁) during a first time interval; charging, by a directcurrent (DC) input current derived from the input electric powerreceived at the power input port, a plurality of batteries of thevehicle charging system by storing a charge in the plurality ofbatteries during the first time interval in which the input electricpower is being received from the power source; determining, by a systemcontroller of the vehicle charging system, occurrence of a triggeringcondition indicating the input electric power is not being received fromthe power source; and in response to determining occurrence of thetriggering condition, controlling, by the system controller, the vehiclecharging system during a second time interval in which the inputelectric power is not being received from the power source to: provide,via a vehicle coupling, a DC charging current at a second voltage (V₂)derived from the plurality of batteries to the vehicle in order tocharge a vehicle battery of the vehicle; provide, by a resilient powersubsystem, a DC operating current at a third voltage (V₃) derived fromelectric power stored in at least one of the plurality of batteries to aplurality of system components within the vehicle charging system,wherein the system components are configured to control operation of thevehicle charging system.
 10. The method of claim 9, wherein theplurality of system components include the system controller.
 11. Themethod of claim 9, wherein: the input electric power is an alternatingcurrent (AC) input electric power received from an electric power grid;and charging the plurality of batteries further comprises producing, viaa rectifier of the vehicle charging system, the DC input current fromthe AC input electric power and providing the DC input current to theplurality of batteries.
 12. The method of claim 9, wherein: each of theplurality of batteries stores the electric power at a fourth voltage(V₄); and the second, third, and fourth voltages satisfy the followingcriteria: V₃<V₄<V₂.
 13. The method of claim 12, wherein the resilientpower subsystem comprises a step-down converter configured to receive abattery current from the at least one of the plurality of batteries atthe fourth voltage (V₄) and provide the DC operating current at thethird voltage (V₃) to the plurality of system components.
 14. The methodof claim 9, wherein the resilient power subsystem provides the DCoperating current to the plurality of system components via a DC bus.15. The method of claim 9, wherein the plurality of system componentscomprise a plurality of temperature control components configured tomaintain an internal temperature of the vehicle charging system withinan operating range.
 16. The method of claim 9, further comprising:providing, by the resilient power subsystem, the DC operating current tothe plurality of system components during the first time interval inwhich the input electric power is being received from the power source.17. The method of claim 9, further comprising: controlling, by thesystem controller, the vehicle charging system during the first timeinterval in which the input electric power is being received from thepower source to: provide, via the vehicle coupling, the DC chargingcurrent at the second voltage (V₂) from the plurality of batteries tothe vehicle in order to charge the vehicle battery of the vehicle. 18.The method of claim 9, further comprising: providing, by a primary powersubsystem of the vehicle charging system, the DC operating current tothe plurality of system components during the first time interval inwhich the input electric power is being received from the power source,wherein the primary power subsystem derives the DC operating currentfrom the input electric power received from the power source.
 19. Themethod of claim 18, wherein the primary power subsystem comprises arectifier configured to receive the input electric power from the powersource as an alternating current (AC) input electric power and producethe DC operating current from the AC input electric power.
 20. Themethod of claim 18, wherein determining occurrence of the triggeringcondition further comprises detecting no power is being received at thepower input port based upon sensor data from one or more sensors.